Storm Events Database
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Storm Events Database
Event Details:
| Event | Tornado |
| -- Scale | EFU |
| -- Length | 1.18 Miles |
| -- Width | 20 Yards |
| State | IOWA |
| County/Area | POCAHONTAS |
| WFO | DMX |
| Report Source | Other Federal Agency |
| NCEI Data Source | CSV |
| Begin Date | 2021-08-20 19:03 CST-6 |
| Begin Location | 2WNW BLANDEN |
| Begin Lat/Lon | 42.5925/-94.6291 |
| End Date | 2021-08-20 19:05 CST-6 |
| End Location | 1NNW BLANDEN |
| End Lat/Lon | 42.6002/-94.6083 |
| Deaths Direct/Indirect | 0/0 (fatality details below, when available...) |
| Injuries Direct/Indirect | 0/0 |
| Property Damage | 0.00K |
| Crop Damage | 0.50K |
| Episode Narrative | Pre-frontal (warm sector) and cold frontal forced thunderstorms (linear and multicellular) moved across portions of northern Iowa during the evening hours of August 20th producing three tornadoes and heavy rainfall. Environmental conditions were favorable for strong to severe storms, including MUCAPE in excess of 3000-4000 J/kg, bulk effective shear around 30 kts ahead of and around 40 kts along the front, 0-3 km bulk shear around 30 to 35 kts roughly perpendicular to storms (especially those ahead of the front), and LCLs around and under 1000m. |
| Event Narrative | Weak tornado southwest of Palmer remained in rural agricultural fields. Path was determined using high resolution satellite imagery. No damage indicators were impacted, hence the EFU rating. |
Event Map:
Note: The tornado track is approximate based on the beginning (B) and ending (E) locations. The actual tornado path may differ from a straight line.
All events for this episode:
| Location | County/Zone | St. | Date | Time | T.Z. | Type | Mag | Dth | Inj | PrD | CrD |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Totals: | 0 | 0 | 0.00K | 2.50K | |||||||
| ALGONA | KOSSUTH CO. | IA | 08/20/2021 | 07:00 | CST-6 | Heavy Rain | 0 | 0 | 0.00K | 0.00K | |
| BADGER | WEBSTER CO. | IA | 08/20/2021 | 07:00 | CST-6 | Heavy Rain | 0 | 0 | 0.00K | 0.00K | |
| CLARION | WRIGHT CO. | IA | 08/20/2021 | 07:00 | CST-6 | Heavy Rain | 0 | 0 | 0.00K | 0.00K | |
| CONRAD | GRUNDY CO. | IA | 08/20/2021 | 07:00 | CST-6 | Heavy Rain | 0 | 0 | 0.00K | 0.00K | |
| GRUNDY CENTER | GRUNDY CO. | IA | 08/20/2021 | 07:00 | CST-6 | Heavy Rain | 0 | 0 | 0.00K | 0.00K | |
| POCAHONTAS | POCAHONTAS CO. | IA | 08/20/2021 | 07:00 | CST-6 | Heavy Rain | 0 | 0 | 0.00K | 0.00K | |
| WEBSTER CITY | HAMILTON CO. | IA | 08/20/2021 | 07:00 | CST-6 | Heavy Rain | 0 | 0 | 0.00K | 0.00K | |
| POCAHONTAS | POCAHONTAS CO. | IA | 08/20/2021 | 15:00 | CST-6 | Heavy Rain | 0 | 0 | 0.00K | 0.00K | |
| BLANDEN | POCAHONTAS CO. | IA | 08/20/2021 | 19:03 | CST-6 | Tornado | EFU | 0 | 0 | 0.00K | 0.50K |
| UNIQUE | HUMBOLDT CO. | IA | 08/20/2021 | 19:19 | CST-6 | Tornado | EFU | 0 | 0 | 0.00K | 1.00K |
| GOLDFIELD | WRIGHT CO. | IA | 08/20/2021 | 20:05 | CST-6 | Tornado | EF0 | 0 | 0 | 0.00K | 1.00K |
| Totals: | 0 | 0 | 0.00K | 2.50K |
